Fix occasional NPE on bungeecord (if a player is not on a server)

platforms/bungeecord/src/main/java/us/ajg0702/queue/platforms/bungeecord/players/BungeePlayer.java

@@ -118,6 +118,7 @@ public class BungeePlayer implements AdaptedPlayer, Audience {
 
     @Override
     public String getServerName() {
+        if(handle.getServer() == null) return null;
         return handle.getServer().getInfo().getName();
     }